Here's a sketch I did yesterday called "Behind the Diner," painted in casein on location in Red Hook, New York.
Incidentally, the blue colors aren't this intense--has anyone noticed that Blogger seems to have installed an auto-color enhancer algorithm?
EDIT: Thanks to Stuart for researching about the auto-enhance feature on Google plus (see comments). I went into Google Plus settings and deactivated that setting. Here's the image with the auto-enhance turned off, which is a lot closer to the original:
You can see a step-by-step sequence with more steps that you can click through, on my public Facebook page.
Here's more about the tools I was using:
Casein tube colors
1/4 inch flat brush
Moleskine watercolor notebook
Waterman Phileas red fountain pen